1. Technical Field
The present invention is related to a touch sensing electrode structure; in particular, it's related to the sensing electrode structure applied to a touch panel.
2. Description of Related Art
A general touch panel adopts one or two layers of electrode plates for the purpose of sensing touching positions. In the conventional technologies, many multi-layer electrode structures have been developed. For example, a capacitance-type touch panel uses the electrodes to sense the capacitive change caused by static electricity when a touching event is made by a user's finger. By which the coordinate positions upon the touch panel can be determined by the electrodes over different directions.
To the electrode materials, it is such as the transparent conductive film made of Indium Tin Oxides (ITO). The demand for large-size touch panel currently requires metal lines to be the electrode structure. The metal lines are such as gold, silver, copper or the like. Through the metal electrode structure of the touch panel, it is achieved that the change of capacitance and the corresponding current over the electrodes may be used to judge the touching positions. In other words, the touching event may result in voltage difference in the coupled capacitors along the sensing electrodes over different directions, and therefore the touching position can be found.
FIG. 1 schematically shows the electrode structure of the conventional technology which is made to technology disclosed in CN102262925 (published on Nov. 30, 2011). The shown electrode structure in a touch panel includes two layers, which are such as a first electrode layer 11 and a second electrode layer 12 with different axial directions. The two electrode layers provide two kinds of axial electrode signals over vertical and horizontal directions respectively.
The electrode structure shown in FIG. 1 is made of fine metal lines. The every metal line winds, turns and cross-connects with each other. According to the disclosure, the every electrode layer forms two or more big lattices along different directions. For example, two or more big lattices are formed over every axial direction. The every big lattice is formed by two or more small lattices. It is noted that some auxiliary patterns are formed next to, but not connected to, the other latters around the edges of the first big lattice. The small latters are the smallest squares. The interconnected and cross-connected metal lines form the electrode structure, and serve to ensure accuracy of sensing the touch-sensing events for avoiding poor sensing caused by any broken line according to one major objective.
The patterns of big lattices over the first electrode layer 11 and the second electrode layer 12 are complementary. There are not too many overlapped portions when the structure overlaps with others. The touching position can be obtained when the signals over the two directions within an area are simultaneously generated with any touching event triggered over the touch panel.
FIG. 2 shows the electrode structure in one touch panel in one other conventional technology. This example is disclosed in TW I346297 (published on Aug. 01, 2011). The described touch panel shows a plate layer 2. On its two surfaces the electrodes over two different directions are formed. The figure shows orthogonal first electrode 21 and second electrode 22. This plate layer 2 is simultaneously to be a partition for isolating the two electrode plates.
A controller 23 is disposed to connect with the first electrode 21  and the second electrode 22. This controller 23 powers the electrode sets (21, 22). An electric field is therefore formed between the first electrode 21 and the second electrode 22. The patterns formed on the first electrode 21 and the second electrode 22 are the latticed metal lines which are in-series connected with each other. These connected latticed metal lines are used to enhance the conductivity of the touch panel.
The mentioned reticular and latticed metal lines forming the patterns on the different types of electrode blocks according to the conventional technologies are to enhance the conductivity of the touch panel and also provide higher accuracy. However, the mentioned reticular or latticed electrode blocks may result in poor quality of a display because the patterns may reduce transmittance of the touch panel and shelter displayed image. Furthermore, the manufacturing process will be much complex since the patterns of reticular or latticed electrode blocks are complicated. Also, the conventional technologies may cost high because the complex patterns needs much more conductive materials.